1. Field Of The Invention
The invention generally relates to an apparatus and method for the manufacture of telephone cables of the type including a single or a plurality of sets of twisted wires.
2. Description Of The Prior Art
Telephone cables of the type which include a plurality of pairs of twinned wires are conventionally manufactured in either two stages or in one stage.
In the case where the cables are manufactured in two stages, the twinned wires are firstly prepared by twisting the wires together by means of so-called "twinning" or "pairing" machines. The twinned wires are then made up into telephone cables by means of, for example, stationary take-ups, so-called rotating take-ups or drum twisting machines.
One form of twinning machine conventionally used for manufacturing twinned wires is the double twist twinning machine. This machine includes a bobbin cradle around which is arranged a rotatable frame or bow which is driven to turn around the cradle. Wires to be twinned may be either supplied from bobbins on the bobbin cradle inside the twinning cage and taken up on a take-up reel outside the twinning cage. The aforementioned arrangement is sometimes referred to as a "inside-out machine". The wires to be twinned may also be supplied from outside of the twinning cage and taken up on a bobbin arranged within the bobbin cradle. The latter configuration is sometimes referred to as an "outside-in machine".
Outside-in machines are generally preferred in single twinners since the wires may be supplied from storage facilities of simple construction and greater capacity. In this case, the bobbin cradle within the twinning cage is also required to hold only a single bobbin. The "outside-in" machine is also readily adaptable for use with a greater number of wires.
If telephone cables are made in one stage, the apparatus involved comprises a plurality of twinning machines of the "inside-out" type. The pairs so manufactured are directed to any type of take-up (e.g. stationary or rotating take ups, single or double twist machines, capstan or extrusion lines) for laying up twinned wires to form a telephone cable. This is done in one operation.
The plurality of double twist twinning machines can be arranged horizontally or vertically, depending on the preferred plant lay out. One typical example of such an installation is disclosed in Canadian Patent No. 997,633.